Prepare potential CAS tag impl

Signed-off-by: TheMode <themode@outlook.fr>

src/main/java/net/minestom/server/tag/TagHandlerImpl.java

@@ -49,19 +49,25 @@ final class TagHandlerImpl implements TagHandler {
             tag.writeUnsafe(viewCompound, value);
             updateContent(viewCompound);
         } else {
-            if (value instanceof NBT nbt) {
-                synchronized (this) {
-                    write(tag, null);
-                    TagNbtSeparator.separate(tag.getKey(), nbt,
-                            entry -> write(entry.tag(), entry.value()));
-                }
+            final Entry<?> entry = valueToEntry(tag, value);
+            updateEntry(tag, entry);
+        }
+    }
+
+    private <T> Entry<?> valueToEntry(Tag<T> tag, @Nullable T value) {
+        if (value == null) return null;
+        if (value instanceof NBT nbt) {
+            if (nbt instanceof NBTCompound compound) {
+                final TagHandlerImpl handler = fromCompound(compound);
+                return new PathEntry(tag.getKey(), handler);
             } else {
-                if (value != null) {
-                    final UnaryOperator<T> copy = tag.copy;
-                    if (copy != null) value = copy.apply(value);
-                }
-                write(tag, value);
+                final var nbtEntry = TagNbtSeparator.separateSingle(tag.getKey(), nbt);
+                return new TagEntry<>(nbtEntry.tag(), nbtEntry.value());
             }
+        } else {
+            final UnaryOperator<T> copy = tag.copy;
+            if (copy != null) value = copy.apply(value);
+            return new TagEntry<>(tag, value);
         }
     }
 
@@ -89,7 +95,7 @@ final class TagHandlerImpl implements TagHandler {
         return updatedCache().compound;
     }
 
-    private synchronized <T> void write(@NotNull Tag<T> tag, @Nullable T value) {
+    private synchronized <T> void updateEntry(@NotNull Tag<T> tag, @Nullable Entry<?> value) {
         int tagIndex = tag.index;
         TagHandlerImpl local = this;
 
@@ -137,7 +143,7 @@ final class TagHandlerImpl implements TagHandler {
             }
         }
         // Normal tag
-        if (value != null) local.entries.put(tagIndex, new TagEntry<>(tag, value));
+        if (value != null) local.entries.put(tagIndex, value);
         else local.entries.remove(tagIndex);
         this.cache = null;
         if (pathHandlers != null) {
@@ -262,7 +268,7 @@ final class TagHandlerImpl implements TagHandler {
         }
 
         @Override
-        public NBT updatedNbt() {
+        public NBTCompound updatedNbt() {
             return value.asCompound();
         }
     }

src/main/java/net/minestom/server/tag/TagNbtSeparator.java

@@ -5,6 +5,7 @@ import org.jglrxavpok.hephaistos.nbt.*;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.Consumer;
 import java.util.function.Function;
 
@@ -33,6 +34,18 @@ final class TagNbtSeparator {
         convert(new ArrayList<>(), key, nbt, consumer);
     }
 
+    static Entry separateSingle(String key, NBT nbt) {
+        assert !(nbt instanceof NBTCompound);
+        AtomicReference<Entry<?>> entryRef = new AtomicReference<>();
+        convert(new ArrayList<>(), key, nbt, entry -> {
+            assert entryRef.getPlain() == null : "Multiple entries found for nbt tag: " + key + " -> " + nbt;
+            entryRef.setPlain(entry);
+        });
+        var entry = entryRef.getPlain();
+        assert entry != null;
+        return entry;
+    }
+
     private static void convert(List<String> path, String key, NBT nbt, Consumer<Entry> consumer) {
         if (nbt instanceof NBTByte nbtByte) {
             consumer.accept(makeEntry(path, Tag.Byte(key), nbtByte.getValue()));

src/test/java/net/minestom/server/tag/TagComponentTest.java

@@ -3,7 +3,8 @@ package net.minestom.server.tag;
 import net.kyori.adventure.text.Component;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 public class TagComponentTest {
 
@@ -13,7 +14,7 @@ public class TagComponentTest {
         var tag = Tag.Component("component");
         var handler = TagHandler.newHandler();
         handler.setTag(tag, component);
-        assertSame(component, handler.getTag(tag));
+        assertEquals(component, handler.getTag(tag));
     }
 
     @Test

src/test/java/net/minestom/server/tag/TagItemTest.java

@@ -8,7 +8,8 @@ import java.lang.ref.WeakReference;
 
 import static net.minestom.server.api.TestUtils.assertEqualsSNBT;
 import static net.minestom.server.api.TestUtils.waitUntilCleared;
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 public class TagItemTest {
 
@@ -19,7 +20,7 @@ public class TagItemTest {
         var handler = TagHandler.newHandler();
         handler.setTag(tag, item);
 
-        assertSame(item, handler.getTag(tag));
+        assertEquals(item, handler.getTag(tag));
     }
 
     @Test
@@ -37,7 +38,7 @@ public class TagItemTest {
         var tag = Tag.ItemStack("item");
         var handler = TagHandler.newHandler();
         handler.setTag(tag, item);
-        assertSame(item, handler.getTag(tag));
+        assertEquals(item, handler.getTag(tag));
 
         handler.setTag(tag, null);
         assertNull(handler.getTag(tag));
@@ -49,7 +50,7 @@ public class TagItemTest {
         var tag = Tag.ItemStack("item");
         var handler = TagHandler.newHandler();
         handler.setTag(tag, item);
-        assertSame(item, handler.getTag(tag));
+        assertEquals(item, handler.getTag(tag));
         handler.setTag(tag, null);
 
         var ref = new WeakReference<>(item);
@@ -66,9 +67,9 @@ public class TagItemTest {
 
         var tag = Tag.ItemStack("item");
         handler.setTag(tag, item);
-        assertSame(item, handler.getTag(tag));
+        assertEquals(item, handler.getTag(tag));
         handler.setTag(tag, item2);
-        assertSame(item2, handler.getTag(tag));
+        assertEquals(item2, handler.getTag(tag));
     }
 
     @Test
@@ -82,7 +83,7 @@ public class TagItemTest {
         // Write the item using the ItemStack tag
         {
             handler.setTag(itemTag, item);
-            assertSame(item, handler.getTag(itemTag));
+            assertEquals(item, handler.getTag(itemTag));
             assertEquals(item.toItemNBT(), handler.getTag(nbtTag));
         }
         // Override it with an NBT tag

src/test/java/net/minestom/server/tag/TagUuidTest.java

@@ -16,7 +16,7 @@ public class TagUuidTest {
         var tag = Tag.UUID("uuid");
         var handler = TagHandler.newHandler();
         handler.setTag(tag, uuid);
-        assertSame(uuid, handler.getTag(tag));
+        assertEquals(uuid, handler.getTag(tag));
     }
 
     @Test